Whisk together flour, baking soda, and baking powder in a small bowl. Using an electric mixer, beat butter and sugar in a large bowl until smooth. Beat in egg and vanilla. Stir in the dry ingredients.
Roll dough out on lightly floured surface. Cut into heart shapes and place on ungreased baking sheets. Dot cookies with red hot candies.
Bake until golden, 8 to 10 minutes. Let stand on cookie sheet for 2 minutes before removing to cooling racks.
